PCF8574_PCF8574A

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© NXP B.V. 2013. All rights reserved.

Product data sheet

Rev. 5 — 27 May 2013

24 of 33

NXP Semiconductors

PCF8574; PCF8574A

For further information on temperature profiles, refer to Application Note AN10365

“Surface mount reflow soldering description”.

18. Soldering of through-hole mount packages

18.1 Introduction to soldering through-hole mount packages

This text gives a very brief insight into wave, dip and manual soldering.

Wave soldering is the preferred method for mounting of through-hole mount IC packages

on a printed-circuit board.

18.2 Soldering by dipping or by solder wave

Driven by legislation and environmental forces the worldwide use of lead-free solder

pastes is increasing. Typical dwell time of the leads in the wave ranges from

3 seconds to 4 seconds at 250

C or 265 C, depending on solder material applied, SnPb

or Pb-free respectively.

The total contact time of successive solder waves must not exceed 5 seconds.

The device may be mounted up to the seating plane, but the temperature of the plastic

printed-circuit board has been pre-heated, forced cooling may be necessary immediately

after soldering to keep the temperature within the permissible limit.

18.3 Manual soldering

Apply the soldering iron (24 V or less) to the lead(s) of the package, either below the

seating plane or not more than 2 mm above it. If the temperature of the soldering iron bit is

less than 300

C it may remain in contact for up to 10 seconds. If the bit temperature is

between 300

C and 400 C, contact may be up to 5 seconds.

MSL: Moisture Sensitivity Level

Fig 21. Temperature profiles for large and small components

001aac844

temperature

time

minimum peak temperature

= minimum soldering temperature

maximum peak temperature

= MSL limit, damage level

peak

temperature